TNValidate - A Fluent Validation Library for .NET

TNValidate is a fluent validation library for .Net. It allows you to write validation logic in a form that is readable both by programmers and non-programmers, but still entirely in your .Net language.
TNValidate has plenty of built-in validation rules, but also provides an extension mechanism to allow you to easily add your own without having to modify the library itself. The library is released under the MIT License.